Histopathological Effects of Hexavalent Chromium in the Ovary of a Fresh Water Fish, Channa punctatus (Bloch) Ashish Kumar Mishra Æ Banalata Mohanty Received: 27 September 2007 / Accepted: 17 March 2008 / Published online: 6 April 2008 Ó Springer Science+Business Media, LLC 2008 Abstract The histopathological effects of hexavalent chromium (Cr VI) in the ovary of a fresh water teleost, Channa punctatus were investigated. An exposure-depen- dent alteration in ovarian histology is reported. For both acute and chronic exposures to Cr (VI), the percentages of atretic oocytes were increased; this increase was more pronounced in the acute exposure group. A decrease in percentage of vitellogenic oocytes was observed in the chronic exposure group indicating impairment of vitello- genesis. The hepatocellular vacuolization and atrophy along with pyknotic nuclei in both acute and chronic chromium exposed fish liver supports the vitellogenic impairment. The observed alterations may be due to both direct cytotoxic effect of Cr (VI) on the ovary as well as mediation by overall systemic toxicity affecting other vital organs. Keywords Hexavalent chromium Á Ovarian histopathology Á Channa punctatus Chromium (Cr), one of the important toxic heavy metals, is released to water bodies through the effluents of various industries. Its indiscriminate introduction into aquatic ecosystem may pose major threat to growth and survival of fish populations. Effects of chromium on the hematological (Gautam and Gupta 1989), biochemical (Jha and Jha 1995), and immune (Arunkumar et al. 2000) parameters as well as histological gill lesions (Nath et al. 1997; Begum et al. 2006) of fish have been reported. However, scientific evi- dence of toxicological impacts of chromium on the fish reproductive system is completely lacking. Recent studies in a few mammal species like mice (Pereira et al. 2005; Acharya et al. 2006), monkey (Aruldhas et al. 2005; Subramanian et al. 2006) and human (Li et al. 2001; Danadevi et al. 2003) determined that chromium acts as a reproductive toxicant. The focus of the present study was therefore, to investigate the Cr (VI) induced ovarian his- topathology of a teleost fish, Channa punctatus both on acute and chronic exposures during the preparatory phase of the reproductive cycle. The vitellogenic growth (vitel- logenin incorporation) of the ovarian follicles takes place during the preparatory phase. Since vitellogenin is syn- thesized in the liver and transported via blood to the ovary to be taken up by growing oocytes (Wallace 1985; Mommsen and Walsh 1988), the impact of chromium on the liver was also evaluated for the correlative assessment. Materials and Methods Adult female specimens of the Channa punctatus (Order: Ophiocephaliformes, Family: Ophiocephalidae) weighing 50 ± 5 g, (length 18 ± 2 cm) were collected from clean and unpolluted local freshwater pond used for fish culture in March 2006, bath treated with 0.1% KMnO 4 solution and acclimatized to laboratory conditions for 2 weeks before experimentation. Fish were maintained in glass aquaria containing seasoned tap water (pH 7.3 ± 0.05, DO 7.5 ± 1.0 mg/L, total hardness 215.3 ± 7.0 mg/L as CaCO 3 and alkalinity 133.2 ± 5.0 mg/L as CaCO 3 ) under natural photoperiod (13L: 11D) and ambient temperature (18–21°C). Fish were provided with commercial dry fish feed pellets ad libitum (Hello fish dry pellets; CVM products, Beijing, China) at approximately 2%–3% of body weight of the fish/day. A. K. Mishra Á B. Mohanty (&) Department of Zoology, University of Allahabad, Allahabad 211002, India e-mail: drbana_mohanty@rediffmail.com 123 Bull Environ Contam Toxicol (2008) 80:507–511 DOI 10.1007/s00128-008-9406-9